JP4957894B2 - Reinforcement method for power transmission towers - Google Patents

Description

  The present invention relates to a power transmission tower constructed in a soft ground zone, in which the power transmission tower is reinforced in a state in which the stress of the power transmission tower pillar material generated by unequal settlement of the power transmission tower foundation is relaxed and released. It is related with the reinforcement method.

  In the soft ground zone in the plain, ground subsidence occurred due to pumping of groundwater during the period of high economic growth, and this trend continues even in some regions. Among power transmission towers constructed in such areas, the foundation for power transmission lines with a relatively large load on the foundation uses pile foundations and mat foundations with higher rigidity. Less susceptible to subsidence. However, small steel towers for secondary transmission lines generally use inverted T-shaped independent foundations, which are generally referred to as standard foundations. Many have been confirmed.

  Conventionally, transmission towers built on soft ground have to undergo some kind of reinforcement work or replacement of the tower when the foundation of the transmission tower is unevenly subsidized and the subsidence exceeds the allowable value. Met.

  As a conventional reinforcing method, for example, in Patent Document 1 below, as shown in FIG. 20, fixing brackets 51, 51 are respectively attached to upper and lower portions of a position to be cut of a power transmission tower main pillar 50. Hydraulic jacks 53 and 53 are mounted on both sides of 51 and 51 in parallel with the main column member 50 via a jack mounting member 52, then a predetermined position of the main column member 50 is cut, and the hydraulic jacks 53 and 53 are connected. After raising or lowering a predetermined dimension by the above method, as shown in FIG. 21, a method of rejoining the upper and lower sides of the support members 50 and 50 cut by the L-shaped steel joint material 54 is disclosed.

Moreover, in the following Patent Document 2, in an existing steel tower composed of pillars in which a number of flanged steel pipes are connected by bolts, a jack is interposed between the upper and lower flanged steel pipes to raise the required height, and a spacer is provided between the flanges. A method of inserting and reconnecting with bolts is disclosed.
JP-A-57-77761 JP 2003-204612 A

  However, since the strut material releases the stress accumulated inside the strut material due to unequal settlement of the power transmission tower foundation after cutting, the cut strut material is rarely located on the same axis. There is always a horizontal (planar) shift between the two cut surfaces. However, in the inventions described in Patent Documents 1 and 2, for example, as shown in FIG. 21, this horizontal shift is forcibly corrected on the same axis, and the post materials 50 and 50 after cutting are joined to the joint material 54. Therefore, there is a problem that secondary stress remains in the support members 50 and 50.

  In addition, although the slope of the transmission tower is temporarily corrected by raising the amount of unequal settlement, there is a risk of further settlement over time due to insufficient strength of the transmission tower foundation. Along with the construction, a construction method that can be easily combined with the strength reinforcement of the transmission tower foundation has been strongly desired.

  Accordingly, a first object of the present invention is to reinforce a power transmission tower in a state in which stress of a column material generated by uneven settlement of a power transmission tower foundation is relaxed and released.

  The second is to reinforce the strength of the power transmission tower foundation together with the reinforcement of the power transmission tower.

In order to solve the above-mentioned problem, the present invention according to claim 1 is a method for reinforcing a power transmission tower that relaxes / releases stress generated in a power tower column material due to uneven settlement of a power transmission tower foundation,
The tower support step of temporarily supporting the power tower tower material with a support steel material via a jack, and removing the concrete at the upper end of the power tower foundation to expose the internal pillar material, this exposed A strut material cutting step in which an arbitrary portion of the strut material is set as a planned cutting position and a supporting plate is fixed to the strut material at the upper and lower portions thereof, and the strut material is cut at the planned cutting position, and the cutting portion is included. Reinforcing bars are placed around the struts, and a formwork is installed on the outer periphery of the struts, and concrete is cast so that the cut struts are displaced and continue to the foundation of the power transmission tower. There is provided a method for reinforcing a power transmission tower comprising a concrete placing process.

  In the present invention according to claim 1, after cutting the pillar material of the power transmission tower, the reinforcing bars are disposed around the pillar material including the cutting portion, and the formwork is installed on the outer periphery thereof, and the steel rod is cut. The concrete was placed so as to be continuous with the power transmission tower foundation while the column material was displaced. Accordingly, the power transmission tower can be reinforced in a state in which the stress generated in the column material is reliably relieved and released by the uneven settlement of the power transmission tower foundation.

  As a second aspect of the present invention, the reinforcing reinforcing bar has a plurality of axial reinforcing bars arranged substantially in parallel with the supporting rod member, and a spiral shape around the axial reinforcing rod group along the circumferential direction of the supporting rod member. A method for reinforcing a power transmission tower according to claim 1, comprising: a helical rebar disposed in a wall.

  In the invention according to the second aspect, the reinforcing reinforcing bars are arranged in a spiral shape along the circumferential direction of the supporting rods around the axial reinforcing bars and the plurality of axial reinforcing bars arranged substantially in parallel with the supporting rods. In particular, the use of spiral rebar as a circumferential reinforcing bar can reduce the anchorage length, and the size of the frame part to be repaired can be reduced. The body can be reinforced without replacing concrete.

  According to a third aspect of the present invention, the reinforcing reinforcing bars are arranged so as to continue to the power transmission tower foundation, and concrete is cast so as to be integrated with the power transmission tower foundation. A method for reinforcing a power transmission tower according to any one of the above is provided.

  In the invention according to the third aspect, the reinforcing reinforcing bars (axial reinforcing bars and spiral reinforcing bars) are arranged so as to continue to the power transmission tower base portion (disposed so as to surround the upper end portion of the steel tower foundation). By placing concrete in the reinforcing bar arrangement region, the reinforcing portion and the steel tower foundation portion are integrally connected, and the reinforcement is performed more firmly. Thereby, it is possible to reinforce against an increase in stress applied to the power transmission tower foundation caused by the displacement of the support material.

  As the present invention according to claim 4, one or more reinforcing piles are driven in advance in the state of being close to the power transmission tower foundation and having a head protruding on the ground surface, and the concrete placing step In any one of Claims 1-3 which arrange | position concrete so that the said formwork may be arrange | positioned including the ground-surface protrusion part of the said reinforcement pile, and the said power transmission tower foundation and the reinforcement pile may be integrated. A method for reinforcing a power transmission tower as described above is provided.

  The present invention according to claim 4 is intended to increase the proof stress of the transmission tower foundation simultaneously with the reinforcement of the transmission tower, in advance, close to the transmission tower foundation to be reinforced, and One or a plurality of reinforcing piles are driven in a state where the head is projected on the ground surface, and in the concrete placing step, including the ground surface protruding portion of the reinforcing pile, the mold is disposed, By placing concrete so that the power transmission tower foundation and the reinforcing pile are integrated, the reinforcement of the power transmission tower foundation is simultaneously performed at the same time as the reinforcement of the tower pillars.

  As the present invention according to claim 5, the mat foundation is disposed in the entire arrangement region of the power transmission tower foundation, and the concrete cast in the concrete placing step is provided connected to the mat foundation. 4. A method for reinforcing a power transmission tower according to any one of 4 is provided.

  The present invention according to claim 5 is also intended to enhance the strength of the power transmission tower foundation at the same time as the reinforcement of the power transmission tower. The concrete cast in the concrete placing process is connected to the mat foundation so that the ground strength is further reinforced by the interaction between the strength of the floor plate of the power transmission tower foundation and the strength of the mat foundation. become.

  As described above in detail, according to the present invention, the power transmission tower can be reinforced in a state where the stress of the column material generated by the uneven settlement of the power transmission tower foundation is relaxed and released. Moreover, simultaneously with the reinforcement of the steel tower, it is possible to easily reinforce the strength of the foundation of the power transmission tower.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  In the method for reinforcing a power transmission tower according to the present invention, as shown in FIG. 1, a plurality of support members 1, 1... A power transmission tower provided with an inverted T-shaped independent foundation (transmission tower foundation 2) composed of 2B is targeted.

  The method for reinforcing a power transmission tower according to the present invention is a method of reinforcing a power transmission tower mainly for the purpose of relaxation / release of stress generated in the column material 1 of the power transmission tower due to unequal settlement of the power transmission tower foundation. is there. Hereinafter, it demonstrates along a procedure.

[First embodiment]
(Steel tower support process)
In the tower support process, as shown in FIG. 2 and FIG. 3, the column material 1 of the power transmission tower is temporarily supported by the support steel material 3 through the jack 4, and the power transmission tower is operated by operating the jack 4 as necessary. Correct. As shown in FIG. 2, the support method using the support steel material 3 is a method of supporting the entire support members 1, 1,... Or a specific support column corresponding to the power transmission tower foundation to be reinforced as shown in FIG. A method of supporting only the material 1 can be adopted.

(Post material cutting process)
Thereafter, as shown in FIG. 4, the surface soil around the target power transmission tower foundation 2 is dug to expose the upper part of the pillar body 2B of the power transmission tower foundation 2, and the column body of the power transmission tower foundation 2 is exposed. The upper (shaded) portion of the concrete is dismantled (suspended) to expose the internal strut material 1. Then, as shown in FIG. 5, an arbitrary portion of the exposed strut material 1 is set as a scheduled cutting position, and a plurality of stages are arranged so as to be suspended from the strut material 1 in the upper and lower portions. .. Are fixed, and then, as shown in FIG. 6, the support material 1 is cut at the planned cutting position. The bearing plate 5 may be fixed after the support material 1 is cut.

  For example, as shown in FIG. 7, the bearing plate 5 uses a member having an L-shaped cross section, and is attached in a state where one surface is suspended from each surface of the column material 1, by bolting, welding, or the like. Fixed to the support material 1.

  After the cutting of the column material 1, the stress accumulated in the column material 1 is released by the distortion of the column material 1 due to the uneven settlement of the power transmission tower foundation so far, as shown in FIG. Then, a positional deviation occurs between the upper column material 1 and the lower column material 1. This positional deviation is usually a positional deviation in the three-dimensional direction of the X, Y, and Z directions.

(Concrete placing process)
In the concrete placing step, first, as shown in FIG. 8, a plurality of axial force bars (also called bending moment bars) 6 around the support material 1 including the cutting portion, substantially parallel to the support material 1, .. Are arranged, and the spiral reinforcing bars 7 are arranged spirally around the axial force bar groups 6, 6. Thereafter, as shown in FIG. 9, a concrete casting form 8 is installed on the outer periphery of the bar arrangement, and the power transmission tower foundation 2 is placed in a state where the cut support material is displaced. Place concrete in a continuous manner. Then, as shown in FIG. 10, the formwork 8 is removed, the surroundings are covered with soil, and the reinforcement work for the transmission tower is completed.

  Thus, in the reinforcing method according to the present invention, the displacement between the support members 1 and 1 in the cut portion is not forcibly corrected, but the stress accumulated in the support member 1 remains in the displaced state. Since the reinforcement measures are performed in a state in which the is released, the long-term stable reinforcement is made.

  The axial force bars 6 and the helical reinforcing bars 7 may be a combination of general axial force bars and hoop bars. Further, as the axial force bar 6, as shown in FIG. 8, a so-called T head bar configured by providing heads 6b and 6b at both ends of the rod 6a, respectively, may be used.

  The helical rebar 7 can generally be arranged densely as compared with a normal hoop rebar, and the structural yield strength can be increased. Therefore, by arranging the helical rebar 7 around the cut portion, the length (height of the fixing portion) can be increased. ) And the width can be kept short, and it is desirable to adopt this reinforcement method which can shorten the bar arrangement time. Moreover, the concrete dismantling range of the steel tower foundation 2 can be reduced, and the construction time can be shortened. In this embodiment, the spiral reinforcing bars 7 are arranged around the axial force bars 6, 6,..., But since the support material 1 is cut, instead of this, a restraining steel pipe (not shown) is used. It may be arranged.

  Further, as shown in FIG. 11, the axial reinforcing bars 6 and the helical reinforcing bars 7 are continuously arranged up to the power transmission tower foundation 2 portion, and concrete is provided in the arrangement area of the axial reinforcing bars 6 and the helical reinforcing bars 7. May be placed. Thereby, the steel tower foundation 2 can be reinforced at the same time, and the strength of the power transmission tower foundation 2 can be increased.

[Second embodiment]
The method for reinforcing a power transmission tower according to the second embodiment of the present invention aims to enhance the strength of the power transmission tower foundation 2 simultaneously with the reinforcement of the power transmission tower. Specifically, as shown in FIG. 12, one or a plurality of reinforcing piles in advance in the state where the head is protruded from the ground surface in the vicinity of the power transmission tower foundation 2 to be reinforced as described above. 10 and 10, and after passing through the tower support process and the strut material cutting process in the same manner as described above, in the concrete placing process, as shown in FIG. The concrete casting form 8 is arranged so that concrete is placed continuously with the power transmission tower foundation 2.

  As shown in FIGS. 14 and 15, the reinforcing portion R constructed in this way can be applied to each of the independent foundations 2, 2... Of the transmission tower, thereby replacing concrete of the existing tower foundation. In addition, the strength of the power transmission tower foundation 2 can be individually strengthened while the power transmission tower is in a state where the power transmission tower has been built, regardless of large-scale reinforcement work such as rebuilding of the steel tower.

[Third embodiment]
Similar to the second embodiment, this embodiment is intended to enhance the strength of the transmission tower foundation 2 at the same time as reinforcing the transmission tower. Specifically, as shown in FIG. 16 and FIG. 17, the reinforcing portion R provided with the mat foundation 11 in the entire arrangement region of the power transmission tower foundations 2, 2, and placed in the concrete placing step. Is provided in connection with the mat base 11. In order to increase the fixing force between the mat foundation 11 and the reinforcing portion R, the concrete shape of the reinforcing portion R is provided with a taper extended upward, or the spiral reinforcement 7 is closely arranged to replace the formwork, It is preferable to place concrete in advance only inside the spiral reinforcing bar 7.

  Conventionally, when a steel tower foundation is reinforced with a mat-type slab, as shown in FIGS. 18 and 19, a fixing member 33 is attached to a pillar portion of the steel tower foundation 30, 30. It was. In such a method, due to the lack of proof strength of the column part of the foundation 30 (lower part reinforced with mat), an increase in the proof strength due to the addition of the slab beam 31 and the power transmission tower foundations 2, 2,. It was necessary to hit the pile 32 to increase its own weight.

  However, in this embodiment, since the pillar portions of the power transmission tower foundations 2, 2... Can be reinforced, the ground strength can be integrally evaluated by the interaction between the strength of the floor board and the strength of the mat foundation 11. The pile can be omitted.

1 is an overall view of a power transmission tower. It is a support procedure figure (the 1) of the tower for power transmission. It is a support procedure figure (the 2) of the steel tower for power transmission. It is a longitudinal cross-sectional view which shows the concrete demolition part of the steel tower foundation 2 for electric power transmission. It is a longitudinal cross-sectional view which shows the cutting plan position of the support | pillar material. It is a longitudinal cross-sectional view which shows the state after the cutting | disconnection of the support | pillar material 1. FIG. The fixing method of the bearing plate 5 to the support | pillar material 1 is shown, (A) is a side view, (B) is the BB line arrow directional view. It is a longitudinal cross-sectional view which shows the bar arrangement state of a reinforcing bar. It is a longitudinal cross-sectional view which shows the placement state of concrete. It is a longitudinal cross-sectional view which shows the power transmission tower after completion | finish of construction. It is a longitudinal cross-sectional view which shows the bar arrangement state of the reinforcing bar which concerns on the other example of a form. It is a longitudinal cross-sectional view which shows the driving | running state of the pile 10 which concerns on a 2nd form example. It is a longitudinal cross-sectional view which shows the placement state of the concrete which concerns on a 2nd form example. It is a longitudinal cross-sectional view which shows the power transmission tower after completion | finish of construction which concerns on a 2nd form example. It is the basic plan. It is a longitudinal cross-sectional view which shows the power transmission tower after completion | finish of construction which concerns on a 3rd form example. It is the basic plan. It is a longitudinal cross-sectional view which shows the power transmission tower after reinforcement by the conventional mat foundation. It is the basic plan. It is a side view of the apparatus used for the reinforcement method of the conventional power transmission tower. It is a perspective view which shows the state couple | bonded with the joint material.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Column material, 2 ... Steel tower foundation for transmission, 3 ... Support steel material, 4 ... Jack, 5 ... Supporting plate, 6 ... Axial reinforcement, 7 ... Spiral reinforcement, 8 ... Formwork

Claims (5)

A method for reinforcing a power transmission tower that relieves and releases stress generated in a power tower pillar material due to uneven settlement of the power transmission tower foundation,
The tower support step of temporarily supporting the power tower tower material with a support steel material via a jack, and removing the concrete at the upper end of the power tower foundation to expose the internal pillar material, this exposed A strut material cutting step in which an arbitrary portion of the strut material is set as a planned cutting position and a supporting plate is fixed to the strut material at the upper and lower portions thereof, and the strut material is cut at the planned cutting position, and the cutting portion is included. Reinforcing bars are placed around the struts, and a formwork is installed on the outer periphery of the struts, and concrete is cast so that the cut struts are displaced and continue to the foundation of the power transmission tower. A method for reinforcing a power transmission tower comprising a concrete placing process.   The reinforcing reinforcing bar is composed of a plurality of axial reinforcing bars arranged substantially in parallel with the supporting rod member, and a helical reinforcing bar arranged in a spiral shape around the axial reinforcing rod group along the circumferential direction of the supporting rod member. Item 2. A method for reinforcing a power transmission tower according to Item 1.   The power transmission tower according to any one of claims 1 and 2, wherein the reinforcing reinforcing bars are arranged so as to continue to the power transmission tower foundation, and concrete is placed so as to be integrated with the power transmission tower foundation. Reinforcement method.   In advance, one or a plurality of reinforcing piles are driven close to the foundation of the power transmission tower and with the head protruding from the ground surface. In the concrete placing step, the ground surface of the reinforcing piles The reinforcement of the transmission tower according to any one of claims 1 to 3, wherein the formwork is arranged including a projecting portion, and concrete is placed so as to integrate the transmission tower foundation and the reinforcing pile. Method.   The power transmission tower according to any one of claims 1 to 4, wherein a mat foundation is disposed in an entire area of the power transmission tower foundation, and the concrete cast in the concrete placing step is connected to the mat foundation. Reinforcement method.

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